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<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        // let strs = 'abcdefhell';
        // console.log(strs.includes('hello'));

        // const arrs = [1,2,3,44];
        // console.log(arrs.includes(4))


        // console.log(3**2);// 3的平方
        // console.log(5**-2);// 5的平方分之一

        // const arr = [1,2,[3,4,[5,6]]];
        // console.log(arr.flat()); // const arr = [1,2,3,4,[5,6]];


        // const arr = [1,2,3];
        // console.log(arr.flatMap(x=>[x*2])) // [2,4,6]


        // const obj = {name:'张三',age:18,height:'181cm'};

        // console.log(Object.values(obj));//['张三', 18, '181cm']
        // console.log(Object.entries(obj)); //[["name","张三"],["age",18],["height","181cm"]]


        const str = 'hello world';
console.log(str.padStart(20,'%'))
console.log(str.padEnd(20,'%'))


    </script>
</body>
</html>